Fuse holders for electric circuits



' Aug. 20 63 I I I URANI 3,

. FUSE HOLDERS FOR ELECTRICICIIRCUITS Filed Nov. 14. 1960 l-lllllllllli "mm/I INVENTOR. ANGELO U/ZA/V/ r 3,101,398 FUSE HOLDERS FOR ELECTRIC CmCUITS Angelo "Urani, St. Louis, Mo., assignor to McGraw-Edison "Company, Elgin, Ill., a corporation of Delaware Filed Nov. 14, 1960, Ser. No. 69,184 4 Claims. (Cl. zoo -129 This inventionrelates to.in1provements in protectors for electric circuits. More particularly, this invention relatesto improvements in holders for electric fuses.

It is therefore an ob ect of the present inventionto provide an improved holder for electric. fuses.

It is frequently desirable to mount a fuse holderinan opening in a panel; and it is oftentimes necessary to mount thatfu se holder in that opening in such a way that the fuse holder will not work loose when the panel is subjected to excessive vibration. Lock washers are frecjuentlyused to try to keep the fuse holder s from working loose; but lock washers are notalways completely effective. Furthermore, lock Washers are objectionable because they do occupy space and they do constitute finite weights. j As a result, it would be desirable to provide-a fuse holder which will not work loose if the panel is vibrated and whichdoes not require a lock washer. The present inven-' tion provides such a fuse holder; and his therefore an object ofthe. present invention to provide a fuse holder Which Will 1101;W0rkl00se if the panel is vibrated and which does not require a lock washer.

The present invention keeps the fuse holder from work- Q 7 ing loose by providing a resilient O-ring at the exterior V of that fuse holdenand by causing that O-ring to engage the opening-defining portions of the panel. The resilient nature of the O-ring enables that O-ring tosubstantially absorb the vibrational forces which could'tend to cause the fuse holder to -work loose; and hence the fuse holder of the present invention will remain in tight engagement with the panel. It is, therefore, an object of the present invention to provide a resilient O-ring at the exterior of ing-defining portions of a panel. I V v The O-ring at the exterior of the fuse holder of the present invention performs an additional function. cifically, that O-ring coacts with that'fuse holder and with the opening-defining portions of the panel to provide a water-tight seal between that fuse holder and that panel. Such a water-tight seal is desirable; and it'is attained in the present invention without the need of any extra arts.

p The O-ring at theexterior of the fuse holder of the presentinvention performs still another function. Specifically, that O-ring serves as a positioning shoulder for the a fuse holder and tocause that O-ring to engage the openfuse holder. In doing so, thatRO-ring determines the eX-' tent to which the body portion of the fuse holder canbe telescoped through an opening in a panel; and it also coacts with a nut or other inexpensive fastener to fixedly hold that body portion in position relative to that panel.

be' disposed within terminals will tend to hold the fuse against dislodgment.

maintained between the prongs of the ICC I Patented Aug. 20, I963 that fuse holder.

terminals of the fuse holden'a'nd those However, if the fuse holder were to be subjected to excessive vibration, the pron-gs of the fuse might tend to work their; way out of those terminals. Those prongs would, howeverpbe wholly unable to wor ofthe closure for limit outward movement of the outer end of the fuse.

Asa result, the closure of the fuse holder of the present invention will make certain that full electrical contact is nals of the fuse holder. 7 r

The closure of the fuse holder of the present invention will, itself, be held against accidental'separation from the body portion of thatfuse holder by the engagement be I tween the end faceiof that closure and the O-ring at the exterior of that fuse holder.

O-ring is made will have a high coeflicient'of frictionj and' hence that O-ring will resist accidental rotation of the closure relative to the body portion of the fuse holder Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description.

In the-drawing and accompanying description a preferred embodiment of the present invention is shown and described but it is to be understood that the dnawing and accompanying description are for the purpose-of illustra tion only .anddo not limit the invention and that the inventionwill be defined by the appended claims. In the drawing,

FIG. 1 is a partially-broken, partially-sectioned side view of a. fuse holder that is made in accordance with the principles and teachings of the present invention, and

' its-hows the manner iii-which thatfuse holder can besecured to "a panel and it also shows the manner'in which that fuse holder can hold a fuse.

Spa

Furthermore, the O-ring at the exterior of the fuse holder of the present invention performs yet another function.

- FIG. 2 isa'side elevational view of [the body portion of I the fuse holder of FIG. 1."

FIG. 3 is a view of the left-hand end of the body por tion:v shown in FIG. 2,

FIG. 4 is a view of the tion shown in FIG. 2,

FIG. 5 is a side elevational view, on an enlarged scale, of one of the terminals that body portion of FIG. 2}

right-hand end of the bodypor- FIG. 6 is an end View, on the scale of FIG. 5, of the right-hand end of the terminal in FIG. 5, and

FIG. 7 is a partially-broken, partially-sectioned side view of the closure for the fuse holder of the present invention. i Referring to the drawing in detail, the numeral 20 generally denotes the body portion of one form of fuse holder that is made in accordance with theprinciples and teachings of the present invention' That body portion is preferablymade from'a plastic material that is sturdy and. tough. The body portion 20 is generally cylindrical, and

it has a cylindrical recess 22 which extends. inwardly from the right-hand end of that body' portion. Theaxis of that recess is parallel to, but is spaced radially outwardly from, thegeometric axis'of the body portion 20. A passage 24 of semi-circular crosssection extends inwardly from the rleft-hand end of the body portion 20; and the axis of that passage is coaxial with'the axis of the cylin That fuse will have prongs which can their way out of those terminals because the closed end the fuse holder would beimmediately adjacent, and would fuse and the termi The material of which that j will be assembled with the drical recess 22. Further, the recess 22 and the passage 24 are contiguous. 1

The bodyportion 20 has a second cylindrical recess, and that second cylindrical recess is denoted by the numeral 26. Similarly, the body portion 20 has a second passage of semi-circular cross section, and that second passage is denoted by the numeral 28. The recess 26 and the passage 28 are contiguous, and their axes are coaxial. 'I hose axes are parallel to the geometric axis of .the body portion 20; and they are located on the same diameter of the body portion 20 OIINVhlCh the axes of the recess 22 and passage 24' are located."

The numeral 30 denotes a prismatic boss which is formed on the left-hand end of the body portion 20. That boss is disposed intermediate the outer endsof the passages 24 andZS; audit will serve as a barrier to any solder which might tend to flow from the region adjacent the outer end of the passage 24 to the region adjacent the outer end of the passage 28 during the time the fuse holder is being soldered into a circuit. The, numeral 32 denotes an annular grooveattheexterior of the body portion 20, and that annular groove-is 1 closer to the right-hand end of that body portion than it is to. the left-hand end of that body portion. -A thread 34 is formed at the exterior of the bodypor'tion 20, and that threadextends forwardly from the annular groove 32. A thread 36 is formed at, the exterior of the body portion 20," and that threads extends ,rearwardly from that annular groove. The direction, pitch and leadof the threads 34 and 3,6jare preferably the same.

The numeral 3,7 denotes a that face which is provided atone side of the exterior of the body portion 20-. That flat facecan engage a flat part of the opening-defining .por-

'tions of a panel; and it will coact with that part to pre vent rotation of the body. portion 20 relative tothat panel. The numeral 38 generally denotes a terminal which is tion. That terminal is preferably formed by rolling a strip of, metal until the left-hand end 40* thereof has a semicircular cross section and until the right-hand end 44 thereof has, a circular cross section. That stripis initially wider at its right-hand'endfthan it is at its lefthand end; and hence that right-hand end can forma substantially complete cylinder. An'elo-ngated slot 42 is formed in the left-hand end'40 of the terminal 38, and that slot-facilitates.the'securement 'of wires or other conductors to that terminal. The circular right-hand end. 44 is flared, asfat 46, and it is slotted,as,at 47. The flaring of that circular portion-facilitates the introduction of the prong of; a fuse'into that circular portion,'and the slotting of that circular portion enables that circular portion. to resiliently grip that prong. The circular portion 44 of the terminal 38 is dimensionedjtoiit loosely within the recess 26 of-the. body portion 20, and the semi-circular'portion 40, is dimensioned to fit snugly within the semi-circular passage 28 in that body portion' The circular portion 44 is dimensioned so the leading edge there'- of is disposed a short distance inwardly of the righthand face of the body portion 20. The left-hand portion 40 of the terminal 38 is dimensioned; so, it projects an appreciable distance outwardly beyond the left-hand faceof the body portion 20. I

. The numeral 48 generally denotes the other terminal of the fuse holder. That terminal is identical in configuration to the terminal 38; but it is inverted so its left-hand, semi-circular end can lit in the passage 24 of semi-circular cross section in the body portion 20. The numeral 50,:denotes an O -ring which is made of 7 rubber, synthetic rubber, elasto-rneric plastic, or the like.

That O-ring will be readily yieldable, andv it will have a high coefficient of friction, That O-ring can be extended to enable ittotelescope over the threaded righthand end. of thebody portion. 20, and it will then retracttolfit. snugly within: the annular recess 3'2 in that body portion. The O-ring 50 will be thick enough so it facilitate wrench-tightening of the nut.

will project outwardly beyond the opening-defining portions of a panel to which the fuse holder is secured.

The numeral 52 denotes a nut which has an internal thread that is complementary to the thread 36 on the body portion 20 of the fuse holder. That nut is prefer ably made of a plastic material that is sturdy and tough. The periphery of the nut 52 is knurled and it is also provided with two flat portions. The knurling facilitates finger-tightening of the nut, and the flat portions The nut 52 will be threaded onto the thread 36 of the body portion 20, and it will be tightened until its front face abuts the rear face of the panel to which the fuse holder .is secured. i

The numeral 54 generally denotes the closure for the fuseholder providedby the present invention That 60 of the closure is dimensioned to engage the. O-ring '50 whenever the cl-osure54 is disposed in assembled relation with the body portion 20 of the fuse holder.

The numeral 62 denotes a panel to which the fuse holder can be secured. That panel has a D-shape'd opening 63 therein, and [the flat side of that opening ;will rea a pant of the fuse holder provided by the present invenceive and hold the flat face 37 on the body portion 20 of the fuse holder. The O-rin-g50 will abut the front face of the panel 6 2; and that O-ring will respond to tightening of the nut 52 to yield and to deform into intimate engagement with the opening-defining portions of that panel; Such an intimate engagement is desirable because it will provide a liquid-tight seal between the body portion 26 and thepanel 62. The yielding and deforming of the O-ring 50 is also =desirable'becauseit enables that O-ring to keep the fuse holder from working loose when the panel 62 is vibrated. It will be noted thta the O-ring 50 serves as a shoulder for the body portion Zl), and thus limits the extent to whichthat body portion can be telescoped through the D-shaped opening 63 in the panel 62. l r

The numeral 64 denotes a fuse of the type shown in Aldino J. Gaia application for protectors for electric circuits which was filed September 19, 1960, and which bears Serial-No. 56,884 and which'is owned by the assignee of this application. That fuse can be made quite smallhaving a length of approximately one-quarter of an inch and having a diameter j of approximately onequarter'of an inclP-and that fuse includes a wholly: enclosed fusible conductor. Two prongs, not shown, extend outwardly from the left-hand end of that fuse; and

those prongs can be telescoped within and tightly held by the terminals 38 and 48 of the fuse holder.

Whenever the fuse 64 has the prongs thereof'fully tele-j I scoped within the right-hand portions of the terminals 38 and 48, the right-hand end of that fuse will be immediately adjacent the inner face of the closedright-hand end 56' of the "closure 54. This is desirable because that closed end of that closure will positively keep the prongs of the fuse 64 from working their Way outof the terminals'38:

and 48.

As the closure 54 is threaded onto the. thread 34 of the body portion 20 of the cfuse holder, the end face, 60

of that closure will abut the right-hand face of the O-ring 50. The resulting engagement will be intimate, and it will provide a liquid-tight seal between the closure 54, and the body portion 20of the fuseholder. In addition,

that engagement will resist rotation of the closure 54 relative to that body portion. In this -Way, the rotation of the closure 54 into engagementwith the O-ringSl) will provide the required sealing of that closure to the body portion 20 and will alsoprevent.accidental-separationof;

that closure from the body portion. 20.

It will thus be seen that the O-ring 50 performs several functions. Forexample, that bring serves as asholdder for the body port-ion 20; Further, that O-ring provides Also, that O-ring serves to provide "a liquid-tight sealv between the closure 54 and the body portion 20. Finally, the O-ring 50 provides resistance to the accidental separation of the closure 54 from the body portion 20. The use of the present invention is not limited to hold ers for electric fuses. For example, the present invention could be used in making sockets for panel-mounted pilot lights, in making small, panel-mounted switches, in making sockets for transistors, in making sockets for vacuum tubes, and in making other panel-mounted devices. As a result, the present invention is very useful and very versatile.

Whereas the drawing and accompanying description have shown and described a preferred embodiment of the present invention, it shouldbe apparent to those skilled in the art that various changes maybe made in the form of the invention without aifecting the scope thereof.

What I claim-1's: 1 i 1. In a panel-mounted holder for electric fuses, a cylindrical body portion that has one end thereof dimensioned to telescope through an opening in a panel and that has the other end thereof adapted to be disposed outwardly of said opening in said panel, an annular-groove in the exterior of said portion intermediate said one and said other ends of said body'portion, a screw thread on the exterior of said bodyportion that extends between said annular groove and said one end of said body portion, a second screw thread on the exterior of said body portion thatextendsbetween said annular groove and said other end of said .body portion, an O-ring that has the inner periphery thereof disposed within and held by said annular groove, the outer'periphery of said O-ring extending radially outwardly beyond the periphery of said one said fastener engaging the first said surfaceon said body I end of said body portion toengage the opening-defining portions of said panel, terminals that are disposed at least partially within said body portion and that, are adapted to accommodate the prongs of an electric fuse, a closure removably mounted on said other end of said body portion, said closure having an internal thread engaging and being held by said second screw thread whenever said closure is in assembled relation with said body portion, said 0-ring constituting a positioning shoulder for said body portion and for said closure and being adapted to serve as the sole positioning shoulder for said body portion and said closure, said 0ring being non-metallic and yieldable and deformable to form a Water tight seal between said panel and said bdoy portion, said O-ring being engageable by said closure to provide a water-tight seal between said body portion and said closure, and a fastener which engages the first said screw thread Whenever said fuseholder. is assembled with said panel and which coacts with said O-ring to hold said body portion in assembled relation with said panel, said second screw thread being adapted t-oreleasably receive said internal thread and thereby releasably hold said closure sembled relation with said body portion.

2. In a panel-mounted holder for electric fuses, a cylindrical body portion that has one end thereof dimen sioned to telescope through an opening in a panel and that has the other end thereof adapted to be disposed outwardly of said opening in saidpanel, fuse-receiving terminals carried by said body portion, an annular groove in the exterior of said body portion intermediate said one and said other ends of said body portion, an Oring that has the inner periphery thereof disposed within and held by said annular groove, the outer periphery of said O-ring extending radially outwardly beyond the periphery of said one end of said body portion to engage the opening-defining portions of said panel,-a closure remov-ably mounted on said other end of said body portion, said O-ring responding to stresses thereon to deform and form a waterin astight seal between said body portion and said openingdefining portions of said panel and to form a water-tight sealbetween said body portion and said closure, said O-ring constituting a positioning shoulder for said. body portion and for said closure and being adapted to serve as the sole positioning shoulder for said body portion and said closure, said 0ring being adapted to substantially absorb vibrational forces tending to cause said body portion to work loose from said panel, a surface on said body portion intermediate said annular groove and said oneend of said body portion that is adapted to receive a stiff fastener which can coact with said O-ring to hold said body portion in assembled relation with said body portion that releasably holds said closure in assembled relation with said body portion, whereby said body portion and said closure can engage each other and can interact with each other to confine an electric fuse, said O-ring being non-metallic and yieldable and deformable,

portion and holding the said O-ring in a stressed and deformed condition adjacent said opening in said panel whenever said device is mounted on a panel.

3. In a panel-mounting holder for electric fuses, a body portion that has one end thereof dimensioned to telescope through an opening in a panel and that has the other end thereof adapted to be disposed outwardly of said opening in said panel, fuse-receiving terminals carried by said body portion, an annular groove in the exterior of said body portion intermediate "said one and said other ends of said body portion, a screw thread on that portion of the exterior of said body portion which is intermediate said annular recess and said one end of said body portion, and an 0-ring disposed partially within and held by said annular groove, said O-ring being non-metallic and defiormable, said O-ring extending outwardly beyond the periphery of said one end ofsaid body portion to'engage i V the opening-defining portions of said panel, said O-ring responding to stresses thereon to deform and form a Water-tightseal between said body portion and said opening-defining portions ofsaid panel, said O-ring constitut-C ing a positioning shoulder for said body portion and being 4. In a panel-mounted holder for electric fuses, a

body portion that has one end thereof dimensioned to telescope through an opening in a panel and that has the-other end thereof adapted to be disposed outwardly of said opening in said panel, fuse-receiving terminals carried by said body portion, a groove in the exterior of said body portion intermediate said one and said other end of said body portion, and a non-metallic and deformable resilient memberdisposed partially within and held by said groove, said resilient member extending outwardly beyond the periphery of said one end of said body portion to engage the opening-defining portions of said panel, said resilient member responding to stresses thereon to deform and form a water-tight seal between said body portion and said opening-defining portions of said panel,

said resilient member constituting a positioning shoulder for said body portion and being adapted to serve as the sole positioning shoulder for said body portion, and a surface on said body portion intermediate said groove and said one end of said body portion that is adapted to receive a stiff fastener and which can hold said fastener at different distances from said groove, whereby said holder. for electric fuses can be mounted on panels of different thicknesses, said fastener and said surface coacting with said resilient member to hold said body portion in assembled relation with said panel, said fastener engaging said surface on saidbody p' ontion and holding said resilient member in stressed and. deformed condition ad: jaeentsaidopeuing in said panel whenever said device is mounted on a panel.

References Cited inthe file of this patent UNIT ED STATES PATENTS 1,601,926 Simpson Oct. 5, 1926 2,610,222

586,415. Burtt et a1. -Sept. 9, 1952 10 d Sundt Apr.v 17, 1956 Sundt Aug. 7, 1956 Podeill et a1. Nov. 12, 1957 Duerkob Sept. 30, 1958 Wanner Apr. 25, 1950 Butler et a1. July '4, 1961 FOREIGN PATENTS Great Britain Mar. 18, 1947 

4. IN A PANEL-MOUNTED HOLDER FOR ELECTRIC FUSES, A BODY PORTION THAT HAS ONE END THEREOF DIMENSIONED TO TELESCOPE THROUGH AN OPENING IN A PANEL AND THAT HAS THE OTHER END THEREOF ADAPTED TO BE DISPOSED OUTWARDLY OF SAID OPENING IN SAID PANEL, FUSE-RECEIVING TERMINALS CARRIED BY SAID BODY PORTION, A GROOVE IN THE EXTERIOR OF SAID BODY PORTION INTERMEDIATE SAID ONE AND SAID OTHER END OF SAID BODY PORTION, AND A NON-METALLIC AND DEFORMABLE RESILIENT MEMBER DISPOSED PARTIALLY WITHIN AND HELD BY SAID GROOVE, SAID RESILIENT MEMBER EXTENDING OUTWARDLY BEYOND THE PERIPHERY OF SAID ONE END OF SAID BODY PORTION TO ENGAGE THE OPENING-DEFINING PORTIONS OF SAID PANEL, SAID RESILIENT MEMBER RESPONDING TO STRESSES THEREON TO DEFORM AND FORM A WATER-TIGHT SEAL BETWEEN SAID BODY PORTION AND SAID OPENING-DEFINING PORTIONS OF SAID PANEL, SAID RESILIENT MEMBER CONSTITUTING A POSITIONING SHOULDER FOR SAID BODY PORTION AND BEING ADAPTED TO SERVE AS THE SOLE POSITIONING SHOULDER FOR SAID BODY PORTION, AND A SURFACE ON SAID BODY PORTION INTERMEDIATE SAID GROOVE AND SAID ONE END OF SAID BODY PORTION THAT IS ADAPTED TO RECEIVE A STIFF FASTENER AND WHICH CAN HOLD SAID FASTENER AT DIFFERENT DISTANCES FROM SAID GROOVE, WHEREBY SAID HOLDER FOR ELECTRIC FUSES CAN BE MOUNTED ON PANELS OF DIFFERENT THICKNESSES, SAID FASTENER AND SAID SURFACE COACTING WITH SAID RESILIENT MEMBER TO HOLD SAID BODY PORTION IN ASSEMBLED RELATION WITH SAID PANEL, SAID FASTENER ENGAGING SAID SURFACE ON SAID BODY PORTION AND HOLDING SAID RESILIENT MEMBER IN STRESSED AND DEFORMED CONDITIN ADJACENT SAID OPENING IN SAID PANEL WHENEVER SAID DEVICE IS MOUNTED ON A PANEL. 